''Protothelenella'' is a genus of fungi in the family Protothelenellaceae. It contains 11 species, some of which form
lichen
A lichen ( , ) is a composite organism that arises from algae or cyanobacteria living among filaments of multiple fungi species in a mutualistic relationship.crustose thallus with spherical to pear-shaped, dark brown to blackish . Microscopic characteristics of the genus include asci with an amyloid , and that are colourless and contain multiple internal partitions. Some species grow on acidic including rocks, soil, bryophytes, plant
detritus
In biology, detritus () is dead particulate organic material, as distinguished from dissolved organic material. Detritus typically includes the bodies or fragments of bodies of dead organisms, and fecal material. Detritus typically hosts commun ...
or rotten wood. Other species are lichenicolous (lichen-dwelling), growing on species of '' Solorina'', ''
Peltigera
''Peltigera'' is a genus of approximately 100 species of foliose lichens in the family Peltigeraceae. Commonly known as the dog or pelt lichens, species of ''Peltigera'' are often terricolous (growing on soil), but can also occur on moss, trees, ...
circumscribed
In geometry, the circumscribed circle or circumcircle of a polygon is a circle that passes through all the vertices of the polygon. The center of this circle is called the circumcenter and its radius is called the circumradius.
Not every polyg ...
by Finnish lichenologist
Veli Räsänen
Veli Johannes Paavo Bartholomeus Räsänen (24 August 1888 – 16 July 1953) was a Finnish lichenologist.
Early life and education
Veli Räsänen was born on 24 August 1888 in Simo, Finland. Räsänen's brother was the linguist Martti Räsä ...
in 1943, with ''Protothelenella reducta'' assigned as the type species. The genus ''
Thelenella
''Thelenella'' is a genus of lichen-forming fungi in the family Thelenellaceae. It has 30 species. The genus was circumscribed by Finnish lichenologist William Nylander in 1855, with '' Thelenella modesta'' assigned as the type species
In zoo ...
'' is similar in some aspects, but differs in the negative iodine
staining
Staining is a technique used to enhance contrast in samples, generally at the microscopic level. Stains and dyes are frequently used in histology (microscopic study of biological tissues), in cytology (microscopic study of cells), and in the ...
of its
ascus
An ascus (; ) is the sexual spore-bearing cell produced in ascomycete fungi. Each ascus usually contains eight ascospores (or octad), produced by meiosis followed, in most species, by a mitotic cell division. However, asci in some genera or s ...
and
hymenial
The hymenium is the tissue layer on the hymenophore of a fungal fruiting body where the cells develop into basidia or asci, which produce spores. In some species all of the cells of the hymenium develop into basidia or asci, while in others some c ...
gel.
A molecular phylogenetics analysis of three ''Protothelenella'' species suggested that the genus is
monophyletic
In cladistics for a group of organisms, monophyly is the condition of being a clade—that is, a group of taxa composed only of a common ancestor (or more precisely an ancestral population) and all of its lineal descendants. Monophyletic gro ...
, and closely related to the species ''
Anzina carneonivea
''Anzina'' is a genus of lichenized fungi of uncertain familial and ordinal classification in the subclass Ostropomycetidae. It is a monotypic genus, containing the single species ''Anzina carneonivea''. This lichen was first described by It ...
''.
Description
''Protothelenella'' either lacks a lichenized thallus or possesses a distinctly lichenized, crustose thallus. The thallus typically appears to cracked- in texture, with a diffuse margin. When fresh, it usually has a bright green colour, but upon drying, the colour changes to whitish or grey-brown. The thallus becomes more or less gelatinous when wet, and it is hardly anatomically differentiated.
The (
photosynthetic
Photosynthesis is a process used by plants and other organisms to convert light energy into chemical energy that, through cellular respiration, can later be released to fuel the organism's activities. Some of this chemical energy is stored in c ...
partner) in ''Protothelenella'' is the
green alga
The green algae (singular: green alga) are a group consisting of the Prasinodermophyta and its unnamed sister which contains the Chlorophyta and Charophyta/Streptophyta. The land plants (Embryophytes) have emerged deep in the Charophyte alga as ...
l genus ''
Elliptochloris
''Elliptochloris'' is a genus of green algae in the order Prasiolales
Prasiolales is an order of green algae in the class Trebouxiophyceae.See the NCBI
The National Center for Biotechnology Information (NCBI) is part of the United Sta ...
'', or it may be absent altogether. Its ascomata, the structures that produce
asci ASCI or Asci may refer to:
* Advertising Standards Council of India
* Asci, the plural of ascus, in fungal anatomy
* Accelerated Strategic Computing Initiative
* American Society for Clinical Investigation
* Argus Sour Crude Index
* Association of ...
(spore-bearing cells), are , which are generally single, scattered, and immersed within the thallus. These perithecia range from spherical to pear-shaped, with colours varying from dark brown to blackish.
The genus does not possess an (an additional protective layer around the perithecium), and its (the outer protective layer of the perithecium) is brown to greenish-blue in the upper part and mostly colourless towards the base. It consists of strongly anastomosing hyphae, measuring up to 1
μm
The micrometre ( international spelling as used by the International Bureau of Weights and Measures; SI symbol: μm) or micrometer (American spelling), also commonly known as a micron, is a unit of length in the International System of Unit ...
in diameter, with narrow .
''Protothelenella'' features a (a network of sterile hyphae among the asci) made up of , which are persistent, strongly branched and anastomosed. are absent in this genus. Its hymenial gel, a gelatinous layer above the ascus layer, reacts to
iodine
Iodine is a chemical element with the symbol I and atomic number 53. The heaviest of the stable halogens, it exists as a semi-lustrous, non-metallic solid at standard conditions that melts to form a deep violet liquid at , and boils to a vi ...
, showing a dull red colour with iodine (I+) and a blue colour when potassium iodide (K/I+) is present. The asci are more or less cylindrical, bearing 6 to 8 spores, and have thick walls (2–5 μm) with two functional layers. The outer wall layer reacts with iodine, turning a dull reddish color (I+) and blue with potassium iodide (K/I+). The ascus apex has an iodine-blue (I+ blue), more or less layered, '' Xylaria''-like ring.
The of ''Protothelenella'' are colourless, contain multiple cross partitions ( septa), and range from somewhat (slightly segmented) to strongly muriform (highly segmented). The outer wall of the spores is distinctly thicker than the septa. The , structures that bear asexual spores or , are not known to occur in this genus.
Chemically, ''Protothelenella'' species may contain an unidentified
substance
Substance may refer to:
* Matter, anything that has mass and takes up space
Chemistry
* Chemical substance, a material with a definite chemical composition
* Drug substance
** Substance abuse, drug-related healthcare and social policy diagnosis ...
that turns red with the application of bleach (C+ red), or they may not contain any specific lichen substances at all.
Habitat and distribution
Members of ''Protothelenella'', including lichenized species, primarily inhabit acidic such as rocks, soil, mosses, plant
detritus
In biology, detritus () is dead particulate organic material, as distinguished from dissolved organic material. Detritus typically includes the bodies or fragments of bodies of dead organisms, and fecal material. Detritus typically hosts commun ...
, and wood, typically in moist environments. In contrast, non-lichenized ''Protothelenella'' species are either lichenicolous (growing on lichens) or found on living mosses.
The genus ''Protothelenella'' is widely distributed, with 11 species found across the Northern Hemisphere and in the austral regions.
Species
The known
hosts
A host is a person responsible for guests at an event or for providing hospitality during it.
Host may also refer to:
Places
*Host, Pennsylvania, a village in Berks County
People
*Jim Host (born 1937), American businessman
*Michel Host ( ...
of the lichenicolous members of ''Protothelenella'' are given, sourced to Diederich and colleagues' 2018 review of lichenicolous fungi. Facultatively lichenicolous fungi typically live independently, but can also live as a lichenicolous species when the conditions are favourable.
* '' Protothelenella corrosa''
* '' Protothelenella croceae'' – host: ''
Solorina crocea
''Solorina crocea'', commonly known as the orange chocolate chip lichen, is a species of terricolous (ground-dwelling) and foliose (leafy) lichen in the family Peltigeraceae. The lichen, which was first formally described by Carl Linnaeus in ...
Stereocaulon
''Stereocaulon'' is a genus of lichens. Members of ''Stereocaulon'' are commonly called snow lichens.
Species
*'' Stereocaulon alpinum''
*'' Stereocaulon apocalypticum''
*'' Stereocaulon arcticum''
*'' Stereocaulon arenarium''
*'' Stereocau ...